Genomic tools are now available for most livestock species and are used routinely for genomic selection (GS) in cattle. One of the most important developments resulting from the introduction of ...genomic testing for dairy cattle is the application of reasonably priced low-density single nucleotide polymorphism technology in the selection of females. In this context, combining genome testing and reproductive biotechnologies in young heifers enables new strategies to generate replacement and elite females in a given period of time. Moreover, multiple markers have been detected in biopsies of preimplantation stage embryos, thus paving the way to develop new strategies based on preimplantation diagnosis and the genetic screening of embryos. Based on recent advances in GS, the present review focuses on new possibilities inherent in reproductive technologies used for commercial purposes and in genetic schemes, possible side effects and beneficial impacts on reproductive efficiency. A particular focus is on the different steps allowing embryo genotyping, including embryo micromanipulation, DNA production and quality assessment.
Genomic selection was simulated in a large dairy cattle population in comparison with a breeding scheme based on bull progeny-testing. The maximum increase of genetic gain (about 80% without cost ...increase) was obtained when bull sires, in much larger number, were selected only based on genomic information, without progeny-testing. In spite of a shorter generation interval, annual inbreeding and coancestry rates were decreased because these bull sires were much more numerous than in the reference scheme. The general recommendation to the AI industry is to pick-up a quite large batch of commercial sires (for breeding regular females) within the set of genomic bull sires, in total contrast with the conventional practice where few bull sires are a selected set of commercial sires, themselves in limited number because selected after progeny-testing. These results obtained in 2009 paved the way for a sustainable genomic selection of French dairy cattle, and are still up to date. Indeed, it is critical for selection and dairy cattle production sustainability to maintain a high enough effective size of the breeds to limit the inbreeding trend. An overview of the first years of activity shows that these recommendations have been well respected on average.
Cet article présente une simulation de sélection génomique dans une grande population de bovins laitiers en comparaison à un programme basé sur le testage des taureaux sur descendance. L’accroissement de progrès génétique est maximum (au moins 80% sans augmentation de coût) quand les pères à taureaux, dont les effectifs sont en forte augmentation, sont sélectionnés uniquement sur information génomique, sans testage sur descendance. Avec ce nombre élevé de pères à taureaux, les coefficients de consanguinité et de parenté diminuent, contrairement à ce qu’on aurait pu craindre compte tenu du raccourcissement de l’intervalle entre générations. Au niveau des éleveurs, la recommandation est de choisir les taureaux d’insémination de service (pères des femelles) en nombre suffisant dans l’ensemble des nombreux pères à taureaux génomiques, en opposition complète avec la pratique générale qui, jusqu’en 2009, consistait au contraire à sélectionner un nombre relativement réduit de taureaux de service parmi les taureaux testés et un nombre encore plus faible de pères à taureaux parmi les taureaux de service. Ces résultats, obtenus en 2009, ont jeté les bases de la gestion des populations bovines laitières en France en sélection génomique, mais ils restent tout à fait d’actualité aujourd’hui. Il est en effet essentiel pour la durabilité de la sélection et de la production que le nombre efficace de reproducteurs soit élevé pour limiter l’augmentation de la consanguinité. L’observation des premières années d’application montre que ces préconisations sont relativement bien suivies en moyenne.
Cet article présente une simulation de sélection génomique dans une grande population de bovins laitiers en comparaison à un programme basé sur le testage des taureaux sur descendance. ...L’accroissement de progrès génétique est maximum (au moins 80% sans augmentation de coût) quand les pères à taureaux, dont les effectifs sont en forte augmentation, sont sélectionnés uniquement sur information génomique, sans testage sur descendance. Avec ce nombre élevé de pères à taureaux, les coefficients de consanguinité et de parenté diminuent, contrairement à ce qu’on aurait pu craindre compte tenu du raccourcissement de l’intervalle entre générations. Au niveau des éleveurs, la recommandation est de choisir les taureaux d’insémination de service (pères des femelles) en nombre suffisant dans l’ensemble des nombreux pères à taureaux génomiques, en opposition complète avec la pratique générale qui, jusqu’en 2009, consistait au contraire à sélectionner un nombre relativement réduit de taureaux de service parmi les taureaux testés et un nombre encore plus faible de pères à taureaux parmi les taureaux de service. Ces résultats, obtenus en 2009, ont jeté les bases de la gestion des populations bovines laitières en France en sélection génomique, mais ils restent tout à fait d’actualité aujourd’hui. Il est en effet essentiel pour la durabilité de la sélection et de la production que le nombre efficace de reproducteurs soit élevé pour limiter l’augmentation de la consanguinité. L’observation des premières années d’application montre que ces préconisations sont relativement bien suivies en moyenne.
Genomic selection was simulated in a large dairy cattle population in comparison with a breeding scheme based on bull progeny-testing. The maximum increase of genetic gain (about 80% without cost increase) was obtained when bull sires, in much larger number, were selected only based on genomic information, without progeny-testing. In spite of a shorter generation interval, annual inbreeding and coancestry rates were decreased because these bull sires were much more numerous than in the reference scheme. The general recommendation to the AI industry is to pick-up a quite large batch of commercial sires (for breeding regular females) within the set of genomic bull sires, in total contrast with the conventional practice where few bull sires are a selected set of commercial sires, themselves in limited number because selected after progeny-testing. These results obtained in 2009 paved the way for a sustainable genomic selection of French dairy cattle, and are still up to date. Indeed, it is critical for selection and dairy cattle production sustainability to maintain a high enough effective size of the breeds to limit the inbreeding trend. An overview of the first years of activity shows that these recommendations have been well respected on average.
Cet article présente une simulation de sélection génomique dans une grande population de bovins laitiers en comparaison à un programme basé sur le testage des taureaux sur descendance. ...L’accroissement de progrès génétique est maximum (au moins 80% sans augmentation de coût) quand les pères à taureaux, dont les effectifs sont en forte augmentation, sont sélectionnés uniquement sur information génomique, sans testage sur descendance. Avec ce nombre élevé de pères à taureaux, les coefficients de consanguinité et de parenté diminuent, contrairement à ce qu’on aurait pu craindre compte tenu du raccourcissement de l’intervalle entre générations. Au niveau des éleveurs, la recommandation est de choisir les taureaux d’insémination de service (pères des femelles) en nombre suffisant dans l’ensemble des nombreux pères à taureaux génomiques, en opposition complète avec la pratique générale qui, jusqu’en 2009, consistait au contraire à sélectionner un nombre relativement réduit de taureaux de service parmi les taureaux testés et un nombre encore plus faible de pères à taureaux parmi les taureaux de service. Ces résultats, obtenus en 2009, ont jeté les bases de la gestion des populations bovines laitières en France en sélection génomique, mais ils restent tout à fait d’actualité aujourd’hui. Il est en effet essentiel pour la durabilité de la sélection et de la production que le nombre efficace de reproducteurs soit élevé pour limiter l’augmentation de la consanguinité. L’observation des premières années d’application montre que ces préconisations sont relativement bien suivies en moyenne.
Genomic selection was simulated in a large dairy cattle population in comparison with a breeding scheme based on bull progeny-testing. The maximum increase of genetic gain (about 80% without cost increase) was obtained when bull sires, in much larger number, were selected only based on genomic information, without progeny-testing. In spite of a shorter generation interval, annual inbreeding and coancestry rates were decreased because these bull sires were much more numerous than in the reference scheme. The general recommendation to the AI industry is to pick-up a quite large batch of commercial sires (for breeding regular females) within the set of genomic bull sires, in total contrast with the conventional practice where few bull sires are a selected set of commercial sires, themselves in limited number because selected after progeny-testing. These results obtained in 2009 paved the way for a sustainable genomic selection of French dairy cattle, and are still up to date. Indeed, it is critical for selection and dairy cattle production sustainability to maintain a high enough effective size of the breeds to limit the inbreeding trend. An overview of the first years of activity shows that these recommendations have been well respected on average.
Simulation des potentialités de la sélection génomique chez les bovins laitiers Colleau , Jean-Jacques (INRA , Jouy-En-Josas (France). UMR 1313 Génétique Animale et Biologie Intégrative); FRITZ , Sebastien (INRA , Jouy-En-Josas (France). UMR 1313 Génétique Animale et Biologie Intégrative); Guillaume , Francois (INRA , Jouy-En-Josas (France). UMR 1313 Génétique Animale et Biologie Intégrative) ...
2009
Conference Proceeding
A potential valorization pathway for pyrolysis oils from lignocellulosic biomass is their co-hydrotreatment with petroleum cuts to produce transportation fuels. The study of simultaneous ...hydrodeoxygenation (HDO) and hydrodesulfurization (HDS) reactions is therefore essential before considering such a co-treatment. The influence of different oxygenated compounds on the hydrotreatment of a straight-run gas oil was studied on a CoMo/γ-Al2O3 catalyst and under industrial operating conditions. The selected compounds were 2-propanol, cyclopentanone, anisole, guaiacol, propanoic acid, and ethyldecanoate, which are representative of the oxygenated chemical families present in bio-oils. Reaction schemes of HDO reactions were proposed for each studied oxygenated compound, and their impact on the gas oil HDS, hydrodenitrogenation (HDN), and aromatic ring hydrogenation (HDCA) was determined. Under our operating conditions, 2-propanol, cyclopentanone, anisole, and guaiacol were not found to be inhibitors of catalytic performances. On the contrary, propanoic acid and ethyldecanoate had an inhibiting effect on HDS, HDN, and HDCA reactions. This inhibition is attributed to a competition between the HDS reactions and the methanation of CO and CO2 formed during the decomposition of ethers and acids. The impact on HDS conversion of dibenzothiophenic compounds was also studied, showing no differences of the inhibiting effect between these molecules.
A potential valorization pathway for liquids obtained from lignocellulosic biomass could be their cohydrotreatment with petroleum cuts to produce transportation fuels. Thus, under hydrotreating ...conditions, biomass compounds are converted through HDO and decarbylation/decarboxylation reactions, leading to the production of CO, CO2, and water. Therefore, it seems essential to consider the impact of COx on the performance of an HDT catalyst in the conversion of a straight run gas oil (SRGO), working under industrial conditions. The conversion of the SRGO was performed at 330 °C, LHSV = 1 h−1, and 5 MPa on a commercial CoMo/Al2O3 sulfided catalyst in the presence of various concentrations of COx (0.0 < molar flow of CO or CO2 < 13.4 mmol/h). The introduction of COx inhibits the HDS and HDN reactions and, to a lesser extent, the hydrogenation of aromatics. Water gas shift and methanation reactions compete with HDT reactions, methane being the major product, and WGS equilibria govern the distribution of the remaining unconverted COx. The formed water is not responsible for the inhibition. From our experiments, it is clear that the inhibition previously observed in the coprocessing of esters or acids (propanoic acid and ethyldecanoate) can be attributed to the COx formed during the reaction.
As solar energy is a variable power source, solar power plants are facing transients that are not experienced in conventional power plants such as nuclear or fossil ones. It is thus of primary ...importance to be able to simulate the dynamic behavior of the solar plants for their design and operation. The regulation modes have to be decided and the operation strategy has to be optimized. Using concentrated solar energy enables to convert solar power into heat before running thermodynamic cycles. Thermal inertia of the systems along with possible heat thermal storages help to smooth solar variations provided that these systems can be managed dynamically. Two solar power plants (with oil or water/steam as heat transfer fluid) are simulated with Dymola using Modelica code. The solar power plant using oil as heat transfer fluid is already running and preliminary results are compared with simulated data. Concerning the solar steam power plant, the model is run to investigate the regulation scheme of the plant that will be commissioned at the end of 2013. For both plant a DNI perturbation is tested and results are discussed concerning the system response and possible improvements.
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